The Radeon 6990 is absolutely the king of single-card performance, but its price makes it essentially unsellable. (Source: Anandtech)

AMD's new card sounds like a jumbo jet and will break the bank, but it is fast

Like the dual-GPU chip Radeon HD 5970, the Radeon HD 6990 [press release] may be a victory lap of sorts for AMD. Unlike the Radeon 5000 series, this generation the chipmaker faced tougher competition, with rival NVIDIA actually delivering in a (relatively) timely fashion an impressive set of GPUs -- the Geforce 500 Series. But sales reports indicate that AMD has maintained its lead over NVIDIA, despite this recovery.

What better way to celebrate than to make a decadent and superfluous, but utterly powerful single card offering?

I. More Beast Than Beauty

While the Radeon HD 6990 is a one-PCB card, it essentially acts like two. It has two distinct vapor chambers, each with their own distinct heat-sink. The GPU chips are linked by an internal CrossFire connection. They share 4 GB of GDDR5 RAM, with each GPU essentially getting 2 GB -- the same as single card offerings from AMD.

Performance-wise the card acts much like two cards as well.

In testing by Anandtech, the card sucked down over 490 watts of power during intense gaming benchmarks. The good news is that it's power dissipation was pretty incredible, allowing the card to stay at a cool 88 degrees Celsius -- one of the best things about the card.

The card can be aggressively overclocked on air up to 830 MHz, at least, but it require power aplenty (almost 550 watts of power, to be precise).

Something not so impressive was the roaring fan speeds required to keep the card running so cool. NVIDIA -- long the butt of many a joke for its Geforce 400 Series' fan noise -- can breathe a sigh of relief. If a Geforce 400 was a noisy lawn mower, the Radeon HD 6990 might as well be a jumbo jet. It generates 70.2 decibels under load -- almost 4 db more than a pair of SLIed Geforce GTX580s. When overclocked the card reached 77 (!) decibels. At those levels, you might want to invest in a nice pair of gamer ear-plugs.

So how's the performance? Well the good news is that this card easily beats any single card on the market right now by NVIDIA or AMD. Sure that's because it's essentially two cards, but if the competition criteria is "single slot card", the Radeon HD 6990 is king.

Against two cards it falls flat, though. It's consistently approximately 8 percent behind a pair of CrossFired AMD Radeon HD 6970 cards. And in some titles like Crysis: Warhead, it even falls behind a pair of Geforce GTX 580s in SLI.

II. "Huh, yeah, what is it good for?" -- Edwin Starr

When it comes to what kind of utility this exercise in extreme single-slot power may have, the answer isn't quite "absolutely nothing", but it's pretty close.

Priced at $700 USD the card is outperformed by a pair of HD 6970s -- approximately $640 USD -- and roughly equaled by a pair of HD 6950s -- approximately $520 USD.

So why in the world would you buy a noisier, less powerful card that's over $60 more expensive? Well, there's a couple reasons why you might -- but they're uncommon.

One is if you have to have 5 monitors. Currently only the 5870 Eyefinity 6 and this card support driving 5 monitors from a single or dual card solution. So if you have to have 5 monitors and you're willing to pay for top power, this is the card for you.

Secondly, if you only have two full PCI-E x16 slots in a board with the slots spaced at least 3 slots apart, and the board is CrossFire-ready, this is your ultimate solution, if heat, noise, and power consumption be damned. Of course, that's because you're really squeezing 4 GPUs into two slots, but that's a minor technicality.

The final candidate would be a very small subset of single-card boards. Generally if you have a single slot, your board/case is too small to sufficiently cool the HD 6990. But it is possible, there are a couple of small systems out there that could muster sufficient cooling for this. Arguably even if such a configuration doesn't exist already, someone could take a micro-ATX case, put a single HD 6990 in it, and pair it with a couple of ridiculous huge fans that cover the walls (maybe 200 mm?).

That would yield a compact, powerful, yet ridiculous expensive system, but the upside would be that it would offer the HD 6990 in a package that might appeal to select few.

Unless AMD somehow cooks up octa-GPU CrossFire drivers, this is card, while a marvel of engineering, is a novelty/niche product, sure to sell few, if any, units.

Much like the protagonists of F. Scott Fitzgerald's "The Beautiful and Damned" the card cuts an attractive figure, but hides ugliness (power, noise, performance) underneath. The upside is that is that it's destined for fame, or perhaps infamy, the downside is that its sales are doomed by its decadence.

"Death Is Very Likely The Single Best Invention Of Life" -- Steve Jobs